Welcome!

That sounds like a rather messy situation. I'm sorry you're dealing with so much!

As a person with a pretty substantial physical disability who is the child of divorced parents... I can only tell you what I know from my own perspective, but I thought I'd give it a shot.

You say you're getting "government help", presumably for childcare related costs for your child with a disability. But are you getting both the provincial AND the federal benefits? There are good programs out there if you want help looking for them (I'm on ODSP in Ontario for instance). You might also qualify for attendant care or respite care at a reduced rate - which could give you a break.

As for your ex - I think perhaps you need to take her to court, to ensure that she provides for your child. That's the only fair thing to do for the child's benefit.